Submission #1197977

#	Time	Username	Problem	Language	Result	Execution time	Memory
1197977		HappyCapybara	Stations (IOI20_stations)	C++17	100 / 100	304 ms	612 KiB

stations

#include "stations.h"
#include<bits/stdc++.h>
using namespace std;

int cnt;
vector<int> in, out, d;
vector<vector<int>> g;

void dfs(int cur, int par){
	d[cur] = d[par]+1;
	in[cur] = cnt;
	cnt++;
	for (int next : g[cur]){
		if (next != par) dfs(next, cur);
	}
	out[cur] = cnt;
	cnt++;
}

vector<int> label(int n, int k, vector<int> u, vector<int> v){
	g.assign(n, {});
	for (int i=0; i<n-1; i++){
		g[u[i]].push_back(v[i]);
		g[v[i]].push_back(u[i]);
	}
	in.assign(n, -1);
	out.assign(n, -1);
	d.assign(n, -1);
	cnt = 0;
	dfs(0, 0);
	vector<int> res(n);
	map<int,int> m;
	for (int i=0; i<n; i++){
		if (d[i] % 2) m[out[i]] = i;
		else m[in[i]] = i;
	}
	auto it = m.begin();
	for (int i=0; i<n; i++){
		res[it->second] = i;
		if (i != n-1) it++;
	}
	return res;
}

int find_next_station(int s, int t, vector<int> c){
	if (c.size() == 1) return c[0];
	int n = c.size();
	if (s == 0){
		for (int i=0; i<n; i++){
			if (t <= c[i]) return c[i];
		}
	}
	bool b = s < c[0];
	if (b){
		if (s < t && t < c[n-2]+1){
			for (int i=0; i<n-1; i++){
				if (t <= c[i]) return c[i];
			}
		}
		else return c[n-1];
	}
	else {
		if (c[1]-1 < t && t < s){
			for (int i=n-1; i>=1; i--){
				if (c[i] <= t) return c[i];
			}
		}
		else return c[0];
	}
}

Compilation message (stderr)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:70:1: warning: control reaches end of non-void function [-Wreturn-type]
   70 | }
      | ^

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 16 / 16
• Subtask 4: 10 / 10
• Subtask 5: 61 / 61